What is MARPOL line and its regulation?

There is also a small diameter line which is used to discharge last part of  the cargo from  the ship is called as MARPOL line .

When cargo discharged has been completed on a cargo system, the pipeline system should also be discharged ashore. The ideal arrangement for this operation is a stripping system which includes a separate, small diameter discharge (MARPOL), line to the midship manifold, with connections to each cargo manifold outboard of the manifold valve.



  • Info required, what are the size requirements for Marpol line on crude or product tankers:
    1. on new tankers
    2. on existing tankers

    What chapter/ regulations/ section of ‘Marpol or SOLAS’ applies to it.


    • Marpol under unified interpretations (no 57) has mentioned the size of this small diamter line. As per the interpretation,For the purpose of application of regulation 30.4.2, the cross sectional area of the small diameter lineshould not exceed:10% of that of a main cargo discharge line for oil tankers delievered after 1 June 1982; or25% of that of a main cargo discharge line for oil tankers delivered on or before 1 June 1982

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